Pins 10 and 11 on the standard Arduino are used by the SPI interface to talk to the Ethernet module.

I'm not familiar with the PowerDriver, but I'm guessing it wants to use them for PWM, which would definitely conflict with the Ethernet.

The Arduino Mega has a different pinout for SPI, so it might solve this conflict for you. However, I think I've also read that some of the PWM pins are different, so it might replace it with a different problem. Someone who knows the Mega well may chime in on this, but you may need to do a little research to find out.

Hi, I have a application written in VB.net that does the sound proccessing, so my "solution" with using the ethernet shield was simply to get communication with the computer... Using the USB cable solved that problem, so v.2 is to try and use a completly integradet solution